Bromeliads (i.e., the family Bromeliaceae) are a family of plants which includes a wide variety of ornamental plants as well as plants valued for their edible fruit. Foremost among the members of the Bromeliaceae family is pineapple which bears a fruit that is valuable both to the commercial producer and to the consumer, both of whom have come to expect certain characteristics in the fruit produced and consumed. For example, while characteristics which are valued by the commercial producer include pest and disease resistance of both the plant and fruit, a high yield of fruit, high brix, and extended shelf-life, those valued by the consumer include low acidity (particularly in winter fruit), low fiber, and uniform fruit shape and color.
Efforts in the pineapple production industry geared to meeting these demands have focused on agroniomic management of crops in order to generate fresh fruit with a total soluble solids (TSS) in the range of 15-20%, titratable acidity of 10.0 to 12.0 with minimal summer to winter variation, and high ascorbic acid (vitamin C) for reduced chilling injury symptom development. Traditionally, meeting these demands has focused on vegetative propagation as well as on breeding of pineapple plants with the desired characteristics. However, extensive breeding efforts have produced only a limited number of new varieties with desirable characteristics. Similarly, while traditional vegetative propagation [e.g.., by means of lateral shoots, basal sucker, or crowns (see, e.g., Collins et al. (1938) J. Heredity 29:163-164)] has been used to propagate pineapple commercially, the limited availability of plant material for vegetative propagation, as well as the slow multiplication rate of vegetatively propagated tissue have prompted the use of an in vitro propagation approach in order to meet the growing worldwide demand for pineapple fruit.
While in vitro culture methods for the generation of pineapple plants are available [Dewald et al (1988) Plant Cell Rep. 7:535-537; Drew et al. (1980) Queesnsland Agr. J. 106:447-451; Firoozabady et al. (1995) In Vitro Cell. Develop. Biol. 31:51A; Hirimburegama et al. (1992) Acta Hort. 319:203-208; Kiss et al. (1995) HortSci 30:127-129; Mapes (1973) Proc. Intl. Plant Propagation Soc. 23:47-55; Mathews et al. (1979) Scientia Horticulturae 11:319-328; Mathews et al. (1981) Scientia Hort. 14:227-234; Wakasa et al. (1978) Japan. J. Breed. 28:113-121; Wakasa (1979) Japan. J. Breed. 29:13-22], attempts to use pineapple tissue culture for the propagation of plants with desirable characteristics have also been unsatisfactory due to the variability in regenerated plants.
What is needed is a better method for producing pineapple plants with desirable characteristics. This method should be amenable to manipulation such that desirable characteristics may be selectively introduced into a pineapple plant which may subsequently be used for the further propagation of pineapple plants with the same characteristics.